Dual power automatic transfer switch can switch to normal power or reserve power automatically. Please note that the switch cannot turn on or turn off the generator. This switch prioritizes normal power. If normal power is available, the switch will connect to normal power. If normal power is off and reserve power is on, the switch will transfer to reserve power. Press the button to Automatic mode, and the switch will automatically transfer between normal and reserve power sources. Press the button to Manual mode, then you must switch the direction manually. Note: Power will be interrupted during switching. TOQ3D is a terminal type automatic transfer device. It is suitable for 3-phase 4-wire (or 1-phase 1-wire) dual power grids with AC 50/60Hz, rated voltage 400V/230V, and rated current up to 63A. When one power source fails (only Phase A voltage is tested for both normal and reserve power; only loss of voltage or phase loss is detected), it automatically connects one or several load circuits from the failed source to the active source to maintain power supply. The automatic transfer switch conforms to IEC60947-6-1 and GB/T14048.11. Color: White Material: ABS Size: 150 x 138 x 111 mm Package Contents: 1 x Dual power automatic transfer switch Only the above package content is included; other products are not included. Note: Lighting and different displays may cause the color of the item in the picture to vary slightly from the actual product. Measurement allows an error of +/- 1-3 cm.